Built-in Node modules

Deno supports using Node.js built-in modules such as fs, path, process, and many more via node: specifiers.

import { readFileSync } from "node:fs";

console.log(fs.readFileSync("deno.json", { encoding: "utf8" }));

Take note that importing via a bare specifier (ex. import { readFileSync } from "fs";) is not supported. If you attempt to do so and the bare specifier matches a Node.js built-in module not found in an import map, Deno will provide a helpful error message asking if you meant to import with the node: prefix. Additionally the LSP provides a quick fix to update to a node: specifier.

If you are using code both with Deno and Node.js, the node: scheme will work in both runtimes and it’s recommended to update to them for your Node.js code anyway.

Node.js compatibility layer

Support for importing Node.js built-in modules is implemented in Deno std’s Node.js compatibility layer. Documentation on which modules are implemented or not can be found in its repository: https://github.com/denoland/deno_std/tree/main/node#deno-nodejs-compatibility